Fast liquid chromatography-tandem mass spectrometry method for the simultaneous determination of phytocannabinoids in oily based preparations

The reported method aims to be a powerful aid for the simultaneous determination of tetrahydrocannabinol (THC), cannabidiol (CBD), cannabinol (CBN), cannabigerol (CBG), tetrahydrocannabinolic acid (THCA), cannabidiolic acid (CBDA), and tetrahydrocannabivarin (THCV) in oily based preparations. The chromatographic separation was carried out using an Hypersil Gold PFP (50 × 2.1 mm, 1.9 μm) column, using H2O + 2 mM ammonium formate + 0.2 % formic acid (M1) and Methanol + 2 mM ammonium formate + 0.2 % formic acid (M2) as mobile phases. The flow rate was set 0.4 mL/min. Specifically, this method was validated in terms of linearity, limit of detections and quantifications (LODs and LOQs), accuracy (precision and trueness, both intra and interday), selectivity, and matrix effects. This procedure allowed quantifying seven phytocannabinoids in less than 10 min. The validated method shows a good linearity within the range 0.25-1000 ng/mL, while precision and trueness (intra- and inter-day) were below <13.25 % and 7.59 %, respectively. Regarding the matrix effect, the method satisfies all the requirements, except for the THC and THCV, where it reaches about 120 %. This element does not affect the method performances as it has been observed that this value is constant and reproducible and therefore does not involve errors in the quantitative analysis. The method was tested and applied on more 70 different oily based preparations. Furthermore, starting from four different cannabis cultivar (FM2, Bedrolite, Bedrocan, and Bediol), it allowed to evaluate the reproducibility of the magistrali preparations. The real samples, in fact, derive from different local pharmacies, and were analyzed by the accredited UNI CEI EN ISO/IEC 17025:2018, Pharmatoxicology Laboratory (ACCREDIA, lab n. 2274 ASLPE, accreditation number 1822 L), accordingly to the current regulations.